Interested still or not?

I have been seeing this guy for about two months, he is older then me I am 24 he is 40, he is divorced and has a child. He usually calls everyday and we talk and we see each other once or twice a week when he does not have his son. well we were supposed to hang out friday night but he cancelled then on saturday he called to tell me he had to go to a basketball game upstate with his son..well saturday was the last time i heard from him, it is now tuesday. Does it sound like he is not interested anymore? and how many days should i wait to see if i hear from him? It is driving me insane I really like him and i am so worried right now...should i call him? wait for him to call and how many days? and does it sound like he may not be interested anymore?